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Chow, T. L., Rees, H. W., Fahmy, S. H. and Monteith, J. O. 2003. Effects of pulp fibre on soil physical properties and soil erosion under simulated rainfall. Can. J. Soil Sci. 83: 109-119. Pulp fibre, a primary type of sludge of pulp and paper mills containing approximately 40% organic C, is usually disposed of in landfills causing a potential environmental problem. This material may be used as a soil amendment to restore the productivity of organic-matter-depleted potato-producing soils in Atlantic Canada. The effect of incorporating this material at rates equivalent to 0.5, 1.0, 2.0, and 4.0% organic matter in the plow layer of a gravelly loam soil on selected soil physical properties and soil erosion was evaluated. The objectives were to determine the effect of pulp fibre additions on selected soil properties, which are pertinent to water retention and movement and to evaluate its effectiveness in reducing runoff and soil loss, major contributing processes to soil degradation. Chemical analysis of pulp fibre revealed that all heavy metal concentrations were well below allowable concentrations for Category A compost. One year after incorporation, bulk density of the Ap horizon had decreased with increasing rates of organic matter addition. On the other hand, the saturated hydraulic conductivity and specific moisture content increased with increasing rates of treatments. Results on water-stable aggregates revealed that the organic matter in the pulp fibre combined smaller aggregates to form larger aggregates, resulting in a larger proportion of macropores as compared to micropores. In the 4% organic matter treatment, a 27% increase was found in the 1.0 to 5.0 mm-diameter aggregates whereas a 23% reduction was found in aggregates smaller than 1.0 mm diameter. In spite of the higher specific moisture content of the organic-matter-treated soils, soil moisture content measured immediately prior to the erosion test indicated that field soil moisture contents were lower than those of the control. Time of runoff initiation, rates of runoff and soil loss were greatly improved with the amendments. The beneficial effects of the 4% organic matter treatment include 2.1 times delay in runoff initiation, and 23 and 71% reduction in runoff and soil loss, respectively. Although the beneficial effects in soil and water conservation are apparent, a minor drawback appears to be lower field soil moisture content. Large-scale implementation of the addition of this material in potato fields should proceed only with caution. . D'habitude, on se débarrasse de la fibre de pâte à papier, important résidu des usines de pâte renfermant environ 40 % de carbone organique, en l'enfouissant dans les décharges contrôlées, ce qui, à la longue, peut poser des problèmes au niveau de l'environnement. Ce matériau pourrait toutefois aussi servir d'amendement et rendre leur fertilité aux terres servant à la culture de la pomme de terre dans les provinces de l'Atlantique, terres dont on a épuisé la matière organique. Les auteurs ont évalué les effets ...

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Organic matter levels combined with drought periods during the growing season have adverse impacts on rain-fed potato production in coarse textured soils of eastern Canada. Using pulp fiber residues (PFR) may build up soil organic matter, improve crops yield and nutrient uptake, and reduce the need for supplemental irrigation in this region. A box experiment with 3 rates of PFR [0, 45, and 90 Mg ha −1 dry mater carbon (C) basis] with or without supplementary drip irrigation was established in a sandy loam soil in New Brunswick, Canada. Red clover, barley, and potato were cultivated as three crops of the rotation in 1999, 2000, and 2001, respectively. The PFR only applied before red clover in fall 1998. Selected soil chemical and physical properties were measured before planting and after harvest. Crops yield and nitrogen (N), phosphorus (P), and potassium (K) accumulation were determined at harvest. Soil organic-C content, bulk density and water holding capacity were improved by PFR application. Red clover and barley biomass production were significantly increased by PFR application. This effect was promoted by supplemental irrigation. Potato tuber yield was not affected by PFR and it was higher in rain-fed compared to supplementary irrigated system. Although, there was some initial evidence of N immobilization but generally PFR application increased N, P, and K bioavailability. This research has demonstrated that PFR can successfully be used as soil amendment in coarse textured soils without any adverse effect.